I've noticed a problem in a number of my shots, where small natural details end up looking really blocky for some reason. I've noticed this particularly on things like foliage in the distance. Leaves end up looking like smeared, small lines of relatively solid color.
Here's an example from a shot I took along the Mississippi River:
The top is cropped at 100% and the bottom is at 300%. The in this crop, you can really see the problem show up on the light-colored rocks, and it's also visible in the leaves on the trees, and even the ripples in the water.
I'm not normally a pixel-peeper, and this obviously isn't much of an issue for images that are going to be scaled down for web use. However, it's pretty obvious to me at 100%, and I could see it being an issue in prints.
Any idea where this stuff is coming from? I'm currently shooting a Nikon D70s, with a Nikkor 50mm f/1.8, Sigma 10-20mm DG EX, and Sigma 70-300mm APO. As far as I can tell, it's not restricted to one lens, but I can't honestly say I've noticed it with the Nikkor (I don't really use it outdoors a whole ton, though).
My typical workflow is just to import the raws into Lightroom, do any lighting adjustments and color correction, and then export.
Could it be an issue of the 6MP sensor in the D70s simply reaching its limits, or is there maybe an issue with my workflow?
If you want to see the original image with EXIF data, it's here.
Any ideas are most appreciated, thanks!
Here's an example from a shot I took along the Mississippi River:

The top is cropped at 100% and the bottom is at 300%. The in this crop, you can really see the problem show up on the light-colored rocks, and it's also visible in the leaves on the trees, and even the ripples in the water.
I'm not normally a pixel-peeper, and this obviously isn't much of an issue for images that are going to be scaled down for web use. However, it's pretty obvious to me at 100%, and I could see it being an issue in prints.
Any idea where this stuff is coming from? I'm currently shooting a Nikon D70s, with a Nikkor 50mm f/1.8, Sigma 10-20mm DG EX, and Sigma 70-300mm APO. As far as I can tell, it's not restricted to one lens, but I can't honestly say I've noticed it with the Nikkor (I don't really use it outdoors a whole ton, though).
My typical workflow is just to import the raws into Lightroom, do any lighting adjustments and color correction, and then export.
Could it be an issue of the 6MP sensor in the D70s simply reaching its limits, or is there maybe an issue with my workflow?
If you want to see the original image with EXIF data, it's here.
Any ideas are most appreciated, thanks!